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<head>
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    <title>Document</title>
    <script src="/static/js/jquery-3.7.1.min.js"></script>
    <style>
        h1 {
            font: 1em sans-serif;
        }

        .aa {
            font-style: italic;
        }

        .bb {
            color: red;
        }        
    </style>
</head>
<body>
    <div>
        <h1 class="aa" id="t">
            <ul id="x">
                <li>张三</li>
                <li>李四</li>
            </ul>
        </h1>
        <h1 class="aa">
            <ul>
                <li>王五</li>
                <li>老六</li>
            </ul>            
        </h1>
    </div>

    <script>
        let h = $("#x li");
        console.log(h);
        console.log(h[0]);
        h.text('Hello World!');
        h.html('<a href="#">点我</a>');
        console.log(h);



    </script>
</body>
</html>